The Gordon Research Conference on Diffraction Methods in Molecular Biology is an ongoing biannual meeting at which the latest results and methods of macromolecular crystallography are discussed in detail. Since its inception over 27 years ago, this field has been and continues to be at the forefront of structural biology. Much of the subject research is supported by several institutes within the NIH. This application is for partial support of the June 1994 meeting of the Diffraction Methods Gordon Conference. The planned program highlights the most recent and exciting developments in structural biology at the molecular level Topics to be discussed will include new methods of data collection and reduction, improved methods to solve structures, application of crystal structure analysis in drug design, and structural insights into mechanisms of hormonal signal transduction and viral infection. Many new macromolecular structures have been determined recently and will be described at the meeting. The Diffraction Methods Gordon Conference is widely regarded as a unique medium for the exchange of new ideas and methodologies. A small meeting, it consistently attracts the participation of outstanding scientists and fosters their communication with those who are developing their careers.